Jared Loughner "talked about reading Friedrich Nietzsche’s book The Will To Power and embraced ideas about the corrosive, destructive effects of nihilism — a belief in nothing. ... Neighbors ... would not chase after a ball that landed in the Loughners' backyard. 'They had to buy a new one.'"[8]

Loughner failed a urine drug test when he applied to join the U.S. Army, and was rejected for that reason.[13] But as of January 10, 2011, there has been no release of any drug tests performed on Loughner following the shooting. Arizona recently passed a law legalizing medical marijuana.[14] His close friend claimed that Loughner has been drug-free since 2008,[2] but his late-night postings on video game forums within the last year were suggestive of drug use.[15] Friends say he believed the United States was responsible for the 9/11 terrorist attacks. [16]